Impact of Cognitive Disturbances and Clinical Symptoms on Disability in Patients with Paranoid Schizophrenia: A Study of a Bulgarian Clinical Sample.

The study aimed to assess the impact of clinical symptoms and cognitive impairment on disability in patients with paranoid schizophrenia (PS). METHODS: 108 patients with schizophrenia were included (66 male and 42 female). Their average age was 38.86 ± 10.02 years and the disease duration was 12.80 ± 8.20 years, with mean disease onset of 24 years. Clinical symptoms were assessed with the PANSS, and cognitive performance was measured using a seven-item neurocognitive battery. The disability level of the subjects was assessed using the World Health Organization-Disability Assessment Schedule 2.0 (WHO-DAS 2.0). The relation between the variables studied was assessed using Spearman's rank correlation coefficient (rs) at a probability level of p < 0.05. RESULTS: An increase in symptom severity resulted in worsening of the "participation in society" (r = 0.56, p < 0.01), "life activities-household" (r = 0.55, p < 0.01), and "getting along with people" (r = 0.59, p < 0.01) WHO-DAS 2.0 domains. Positive symptoms (13.89 ± 3.48) correlated strongly with "getting along with people" (r = 0.55, p < 0.01), "life activities-household" (r = 0.58, p < 0.01), and "participation in society" (r = 0.62, p < 0.01), and negative symptoms (14.25 ± 4.16) with "participation in society" (r = 0.53, p < 0.01) and "life activities-household" (r = 0.48, p < 0.01). Symptoms of disorganization (15.67 ± 4.16) had the highest impact on "life activities-household" (r = 0.81, p < 0.01), "getting along with people" (r = 0.56, p < 0.05), and "participation in society" (r = 0.65, p < 0.01). Episodic memory (r = -0.28, p < 0.01) was remotely related to comprehension and communication. The information processing speed (rs = 0.38, p < 0.01), visual memory (rs = -0.30, p < 0.01), and focused executive functions showed moderate correlations with all domains on the WHO-DAS 2.0 scale (rs = 0.38, p < 0.01). Attention (rs = -0.33, p < 0.01) was moderately related to community activities. Semantic (rs = -0.29, p < 0.01) and literal (rs = -0.27, p < 0.01) verbal fluency demonstrated weak correlations with "cognition-understanding", "getting along with people", and "participation in society". CONCLUSION: Symptoms of disorganization and disturbed executive functions contribute most to disability in patients with schizophrenia through impairment of real-world functioning, especially in social interactions and communication. Severe clinical symptoms (negative and disorganization-related ones) as well as deficits in executive function, verbal memory, and verbal fluency cause the biggest problems in the functional domains of interaction with other people and participation in society.

Toxoplasma gondii seropositivity and cognitive function in adults with schizophrenia.

Introduction and methods: Based on the limited research focusing on the severity of cognitive deterioration in schizophrenia with preceding toxoplasmosis, we sampled 89 demographically matched paranoid schizophrenia patients (mean age 38.97 years) with (n = 42) and without (n = 47) seroprevalence of IgG type anti T. gondii antibodies as marker of past infection. They underwent examination of verbal memory (10 words Luria test), logical memory and visual memory (BVRT), processing speed (TMT-A/DSST) and executive functions (TMT-B/verbal fluency). We compared the results of both groups, taking into account the normative values for the Bulgarian population where available. We also compared the two groups in terms of clinical severity as evidenced by positive, negative and disorganization sub-scores of the PANSS. Results: While both groups were expectedly under the population norms for verbal and logical memory, seropositive patients showed significantly bigger impairment in verbal memory (Luria Smax = 72.85 vs 78.51; p = 0.029), psychomotor speed (TMT-A 50.98 s vs 44.64 s; p = 0.017), semantic verbal fluency (27.12 vs 30.02; p = 0.011) and literal verbal fluency (17.17 vs 18.78; p = 0.014) compared to the seronegative ones. In addition to that, they gave less correct answers on the BVRT (2.98 vs 4.09; p = 0.006) while making markedly more errors (13.95 vs 10.21; p = 0.002). Despite not reaching statistical significance, past toxoplasmosis was associated with higher score on the PANSS disorganization sub-scale (16.50 points vs 14.72 points) and with lower educational attainment. Conclusion: Our results suggest a more profound neuropathological insult(s) resulting in greater cognitive impairment in schizophrenia cases that are exposed to T. gondii infection.

Corrigendum: Socio-Demographic and Clinical Characteristics of Psychiatric Patients Who Have Committed Suicide: Analysis of Bulgarian Regional Suicidal Registry for 10 Years.

[This corrects the article DOI: 10.3389/fpsyt.2021.665154.].

Socio-Demographic and Clinical Characteristics of Psychiatric Patients Who Have Committed Suicide: Analysis of Bulgarian Regional Suicidal Registry for 10 Years.

Introduction: Suicide is a major public health problem but factors determining suicide risk are still unclear. Studies in this field in Bulgaria are limited, especially on a regional level. Methods: By a cross-sectional design, we accessed the medical records of all psychiatric patients committed suicide over a 10-year period (2009-2018) in one major administrative region of Bulgaria. A statistical analysis was performed of the association between age of suicide as an indirect yet measurable expression of the underlying suicidal diathesis and a number of socio-demographic and clinical characteristics. Results: Seventy-seven of 281 suicides (28%) had psychiatric records. Most common diagnoses were mood disorders (44%), followed by schizophrenia (27%), anxiety disorders (10%), substance use disorders (9%) and organic conditions (8%). Male gender, single/divorced marital status, early illness onset, co-occurring substance misuse and lower educational attainment (for patients aged below 70) were significantly associated with earlier age of suicide whereas past suicide attempts and psychiatric hospitalizations, comorbid somatic conditions and unemployment showed insignificant association. Substantial proportion of patients (60%) had contacted psychiatric service in the year preceding suicide, with nearly half of these encounters being within 30 days of the accident. Conclusion: Severe mental disorders are major suicide risk factor with additional contribution of certain socio-demographic and illness-related characteristics. Monitoring for suicidality must be constant in chronic psychiatric patients. Registration of suicide cases in Bulgaria needs improvement in terms of information concerning mental health. More studies with larger samples and longitudinal design are needed to further elucidate distal and proximal suicide risk factors.

Residues in Transmembrane Segments of the P2X4 Receptor Contribute to Channel Function and Ethanol Sensitivity.

Mouse models of alcohol use disorder (AUD) revealed purinergic P2X4 receptors (P2X4Rs) as a promising target for AUD drug development. We have previously demonstrated that residues at the transmembrane (TM)-ectodomain interface and within the TM1 segment contribute to the formation of an ethanol action pocket in P2X4Rs. In the present study, we tested the hypothesis that there are more residues in TM1 and TM2 segments that are important for the ethanol sensitivity of P2X4Rs. Using site-directed mutagenesis and two electrode voltage-clamp electrophysiology in Xenopus oocytes, we found that arginine at position 33 (R33) in the TM1 segment plays a role in the ethanol sensitivity of P2X4Rs. Molecular models in both closed and open states provided evidence for interactions between R33 and aspartic acid at position 354 (D354) of the neighboring TM2 segment. The loss of ethanol sensitivity in mixtures of wild-type (WT) and reciprocal single mutants, R33D:WT and D354R:WT, versus the WT-like response in R33D-D354R:WT double mutant provided further support for this interaction. Additional findings indicated that valine at TM1 position 49 plays a role in P2X4R function by providing flexibility/stability during channel opening. Collectively, these findings identified new activity sites and suggest the importance of TM1-TM2 interaction for the function and ethanol sensitivity of P2X4Rs.

Prevalence and clinical picture of premenstrual syndrome in females from Bulgaria.

BACKGROUND: Premenstrual syndrome (PMS) and its more severe form premenstrual dysphoric disorder (PMDD) are highly prevalent conditions, but there seems to be ethnic and cultural variances in their distribution. AIMS: To explore the prevalence of PMS/PMDD and their typical clinical features in a Bulgarian population. MATERIALS AND METHODS: This investigation was designed and executed as a cross-sectional descriptive study. Three hundred and five conveniently recruited females with no psychiatric history filled in a self-evaluation questionnaire based on DSM-IV tapping on different symptoms of PMS. The prevalence of the conditions was calculated. RESULTS: 32.1% (N = 98) of the tested females (mean age 31.04 ± 6.31) suffered from PMS and 3.3% (N = 10) were diagnosed with PMDD. The leading symptoms in the sample were irritability, fatigue and changes in appetite, depressed mood, mood swings, and anxiety, and abdominal bloating, breast tension and tenderness. Most of the symptoms were moderately severe. Mild and moderate cases of PMS were near equally distributed and more frequent than severe ones. CONCLUSION: PMS is a common condition which is usually mildly expressed, but severe cases are not an exception. The clinical picture is dominated by almost equally distributed psychological and somatic symptoms.

A Clinical Case of Patient Carrying Rare Pathological PSEN1 Gene Mutation (L424V) Demonstrates the Phenotypic Heterogenity of Early Onset Familial AD.

Dementia comprises several neurodegenerative disorders with similar neuropsychiatric features and Alzheimer's disease (AD) is the most common of them. Genetic factors are strongly implicated into its etiology especially for early-onset cases (EOAD) occuring before the age of 65. About 10% of these are inherited in autosomal dominant fashion via pathogenic polymorphisms in three genes- APP, PSEN-1, and PSEN-2. Despite genotypic clarity, however, phenotypic variability exists with different symptom constellations observed in patients with identical mutations. Below, we present a case of a 39-year-old male with a family history for early onset dementia who was referred to our department with anamnesis for abrupt behavioral change 7 months prior to hospitalization-noticeable slowing of speech and reactivity, impaired occupational functioning and irritability, followed by aphasic symptoms and transient episodes of disorientation. He was followed up for 2 years and manifested rapidly progressing cognitive decline with further deterioration of speech, apraxia, acalculia, ataxia, and subsequently bradykinesia and tremor. Based on the clinical and neuroimaging findings (severe cortical atrophy), familial EOAD was suspected and a whole exome sequence (WES) analysis was performed. It identified a heterozygous missense variant Leu424Val (g.71074C > G) in PSEN-1 gene considered to be pathogenic, and only reported once until now in a Spanish patient in 2009. Despite genotype identity however, distinct phenotypic presentations were observed in the two affected subjects, with different neuroimaging findings, and the presence and absence of seizures in the Spanish and Bulgarian case, respectively. Besides, myoclonus and spastic paraparesis considered "typical" EOAD clinical features were absent. Age of symptom onset was consistent with two of the reported mutations affecting 424 codon of PSEN-1 gene and significantly earlier than the other two implying that factors influencing activity of PSEN-1 pathological forms are yet to be clarified. Furthermore, our patient had co-occurring lupus erythematosus (LE) and we suggest that this condition might be etiologically linked to the PSEN-1 mutation. In addition to illustrating the symptomatic heterogeneity of PSEN-1 caused EOAD, our study confirms that in patients presenting with early cognitive deterioration and family history for dementia, WES can be especially informative and should be considered as a first-line examination.

Tryptophan 46 is a site for ethanol and ivermectin action in P2X4 receptors.

ATP-gated purinergic P2X4 receptors (P2X4Rs) are the most alcohol-sensitive P2XR subtype. We recently reported that ivermectin (IVM), an antiparasitic used in animals and humans, antagonized ethanol inhibition of P2X4Rs. Furthermore, IVM reduced ethanol intake in mice. The first molecular model of the rat P2X4R, built onto the X-ray crystal structure of zebrafish P2X4R, revealed an action pocket for both ethanol and IVM formed by Asp331, Met336 in TM2 and Trp46, and Trp50 in TM1 segments. The role of Asp331 and Met336 was experimentally confirmed. The present study tested the hypothesis that Trp46 plays a role in ethanol and IVM modulation of P2X4Rs. Trp46 was mutated to residues with different physicochemical properties and the resultant mutants tested for ethanol and IVM responses using Xenopus oocyte expression system and two-electrode voltage clamp. Nonaromatic substitutions at position 46 reduced ethanol inhibition at higher concentrations and switched IVM potentiation to inhibition. Simultaneous substitution of alanine at positions Trp46 and Met336 also resulted in similar changes in ethanol and IVM responses. Furthermore, a new molecular model based on the open pore conformation of zebrafish P2X4R suggested a role for Tyr42 that was further supported experimentally. Our previous and current findings, combined with our preliminary evidence of increased ethanol consumption in P2X4R knockout mice, suggest that the ethanol and IVM action pocket in P2X4Rs formed by positions 42, 46, 331, and 336 presents a potential target for medication development for alcohol use disorders.

Ethanol is a fast channel inhibitor of P2X4 receptors.

P2X receptors (P2XRs) are ion channels gated by synaptically released ATP. The P2X4 is the most abundant P2XR subtype expressed in the central nervous system and to date is the most ethanol-sensitive. In addition, genomic findings suggest that P2X4Rs may play a role in alcohol intake/preference. However, little is known regarding how ethanol causes the inhibition of ATP-gated currents in P2X4Rs. We begin to address this issue by investigating the effects of ethanol in wild-type and mutant D331A and M336A P2X4Rs expressed in human embryonic kidney (HEK) 293 cells using whole-cell patch-clamp methods. The results suggest that residues D331 and M336 play a role in P2X4R gating and ethanol inhibits channel functioning via a mechanism different from that in other P2XRs. Key findings from the study include: 1) ethanol inhibits ATP-gated currents in a rapid manner; 2) ethanol inhibition of ATP-gated currents does not depend on voltage and ATP concentration; 3) residues 331 and 336 slow P2X4 current deactivation and regulate the inhibitory effects of ethanol; and 4) ethanol effects are similar in HEK293 cells transfected with P2X4Rs and cultured rat hippocampal neurons transduced with P2X4Rs using a recombinant lentiviral system. Overall, these findings provide key information regarding the mechanism of ethanol action on ATP-gated currents in P2X4Rs and provide new insights into the biophysical properties of P2X4Rs.

Ivermectin antagonizes ethanol inhibition in purinergic P2X4 receptors.

ATP-gated purinergic P2X4 receptors (P2X4Rs) are expressed in the central nervous system and are sensitive to ethanol at intoxicating concentrations. P2XRs are trimeric; each subunit consists of two transmembrane (TM) alpha-helical segments, a large extracellular domain, and intracellular amino and carboxyl terminals. Recent work indicates that position 336 (Met336) in the TM2 segment is critical for ethanol modulation of P2X4Rs. The anthelmintic medication ivermectin (IVM) positively modulates P2X4Rs and is believed to act in the same region as ethanol. The present study tested the hypothesis that IVM can antagonize ethanol action. We investigated IVM and ethanol effects in wild-type and mutant P2X4Rs expressed in Xenopus oocytes by using a two-electrode voltage clamp. IVM antagonized ethanol-induced inhibition of P2X4Rs in a concentration-dependent manner. The size and charge of substitutions at position 336 affected P2X4R sensitivity to both ethanol and IVM. The first molecular model of the rat P2X4R, built onto the X-ray crystal structure of zebrafish P2X4R, revealed a pocket formed by Asp331, Met336, Trp46, and Trp50 that may play a role in the actions of ethanol and IVM. These findings provide the first evidence for IVM antagonism of ethanol effects in P2X4Rs and suggest that the antagonism results from the ability of IVM to interfere with ethanol action on the putative pocket at or near position 336. Taken with the building evidence supporting a role for P2X4Rs in ethanol intake, the present findings suggest that the newly identified alcohol pocket is a potential site for development of medication for alcohol use disorders.

A point mutation in the ectodomain-transmembrane 2 interface eliminates the inhibitory effects of ethanol in P2X4 receptors.

ATP-gated P2X4 receptors (P2X4R) are abundantly expressed in the CNS. However, little is known about the molecular targets for ethanol action in P2X4Rs. The current investigation tested the hypothesis that the ectodomain-transmembrane (TM) interface contains residues that are important for the action of ethanol in P2X4Rs. Wild type (WT) and mutant P2X4R were expressed in Xenopus oocytes. ATP concentration-response curves and ethanol (10-200 mM)-induced changes in ATP EC(10)-gated currents were determined using two-electrode voltage clamp (-70 mV). Alanine substitution at the ectodomain-TM1 interface (positions 50-61) resulted in minimal changes in ethanol response. On the other hand, alanine substitution at the ectodomain-TM2 interface (positions 321-337) identified two key residues (D331 and M336) that significantly reduced ethanol inhibition of ATP-gated currents without causing marked changes in ATP I(max), EC(50), or Hill's slope. Other amino acid substitutions at positions 331 and 336 significantly altered or eliminated the modulatory effects of ethanol. Linear regression analyses revealed a significant relationship between hydropathy and polarity, but not molecular volume/molecular weight of the residues at these two positions. The results support the proposed hypothesis and represent an important step toward developing ethanol-insensitive receptors for investigating the role of P2X4Rs in mediating behavioral effects of ethanol.

Roles of ectodomain and transmembrane regions in ethanol and agonist action in purinergic P2X2 and P2X3 receptors.

The present work investigated sites of ethanol action in ATP-gated P2X receptors (P2XRs) using chimeric strategies that exploited the differences in ethanol response between P2X2R (inhibition) and P2X3R (potentiation). We tested ethanol (10-200mM) effects on ATP- and alpha,beta-methylene-ATP (alpha,beta-meATP)-induced currents in wildtype P2X2, P2X3 and chimeric P2X2/P2X3Rs expressed in Xenopus oocytes using two-electrode voltage-clamp (-70mV). Exchanging ectodomain regions of P2X2 and P2X3Rs reversed wildtype ethanol responses. Substituting back portions of the P2X2R ectodomain at TM interfaces in chimeras that contained the P2X3R ectodomain restored wildtype P2X2R-like ethanol response. Point mutations that replaced non-conserved ectodomain residues at TM interfaces of P2X3Rs with homologous P2X2R residues identified positions that reversed the direction (304) or changed the magnitude (53, 55 and 313) of ethanol response. Homologous substitutions in P2X2Rs did not significantly alter wildtype P2X2R-like ethanol responses. These findings suggest that ectodomain segments at TM interfaces play key roles in determining qualitative and quantitative responses to ethanol of P2X2 and P2X3Rs. Studies that substituted TM regions of P2X3R with respective P2X2R TMs indicate that the TM1, but not the TM2, region plays a role in determining the magnitude of ethanol response. Studies with ATP and alpha,beta-meATP support prior indications that TM regions are important in agonist desensitization and suggest that both ectodomain and TM regions play roles in determining agonist potency and selectivity. Overall, these findings are the first to identify potential targets for ethanol in P2X2 and P2X3Rs and should provide insight into the sites of ethanol action in other P2XRs.